Light emitting device

ABSTRACT

A light emitting device has; a light emitting element, a light reflecting member that is disposed so as to cover the lateral surfaces of the light emitting element and expose a top surface of the light emitting element, a frame that is disposed on the light reflecting member so as to surround an outer periphery of the top surface of the light emitting element, a light transmissive member that is disposed inside the frame, and a sealing member that covers the light reflecting member, the frame and the light transmissive member, and that has a flange covering part of the frame.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No.2015-177089 filed on Sep. 8, 2015. The entire disclosure of JapanesePatent Application No. 2015-177089 is hereby incorporated herein byreference.

BACKGROUND

1. Technical Field

The present disclosure relates to a light emitting device.

2. Description of Related Art

There is a known light emitting device in which light extractionefficiency is improved by forming a lens above the light emittingelement. For example, with the light emitting device discussed inJP2012-156442A, as shown in FIG. 4, a light emitting portion surroundedby a frame is made smaller with respect to the lens diameter, whichallows the angle of incidence of the light beam emitted at the interfacebetween the lens and an air layer to be smaller, and attempt to increasethe light extraction efficiency.

The equipment in which light emitting devices are installed have tendedto be more downsized in recent years, and there is a need for furtherreduction in the size of light emitting devices to be installed. It isan object of the present disclosure to provide a light emitting devicethat can be made more compact.

SUMMARY

A light emitting device of the present disclosure has; a light emittingelement, a light reflecting member that is disposed so as to cover thelateral surfaces of the light emitting element and expose a top surfaceof the light emitting element, a frame that is disposed on the lightreflecting member so as to surround an outer periphery of the topsurface of the light emitting element, a light transmissive member thatlight transmissive and is disposed inside the frame, and a sealingmember that covers the light reflecting member, the frame and the lighttransmissive member, and that has a flange covering part of the frame.

Disclosed herein is a light emitting device, wherein it is possible toprovide a light emitting device that can be made more compact.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic top view of the light emitting device inEmbodiment 1;

FIG. 2 is a schematic cross sectional view along the A-A′ line in FIG.1;

FIG. 3 is a schematic lower view of the light emitting device inEmbodiment 1;

FIG. 4 is a partially enlarged view of FIG. 2;

FIG. 5A is a schematic top view and FIG. 5B is a schematic lateral sideview, respectively showing a method for manufacturing the light emittingdevice in Embodiment 1;

FIG. 6A is a schematic top view and FIG. 6B is a schematic lateral sideview, respectively showing a method for manufacturing the light emittingdevice in Embodiment 1;

FIG. 7A is a schematic top view and FIG. 7B is a schematic crosssectional view along the B-B′ line in FIG. 7A, respectively showing amethod for manufacturing the light emitting device in Embodiment 1;

FIG. 8A is a schematic top view and FIG. 8B is a schematic crosssectional view along the C-C′ line in FIG. 8A, respectively showing amethod for manufacturing the light emitting device in Embodiment 1;

FIG. 9A is a schematic top view and FIG. 9B is a schematic crosssectional view along the D-D′ line in FIG. 9, respectively showing amethod for manufacturing the light emitting device in Embodiment 1;

FIG. 10A is a schematic top view and FIG. 10B is a schematic lateralside view, respectively showing a method for manufacturing the lightemitting device in Embodiment 1;

FIG. 11 is a schematic plane view of the wiring in the light emittingdevice in Embodiment 1;

FIG. 12 is a schematic cross sectional view of the light emitting devicein Embodiment 2;

FIG. 13 is a schematic cross sectional view showing a method formanufacturing the light emitting device in Embodiment 2; and

FIG. 14 is a schematic partial enlarged view of the main parts of thelight emitting device in Embodiment 3.

DETAILED DESCRIPTION

In the following description, terms will be used to indicate particulardirections or positions as needed (such as “upper,” “lower,” “left,”“right,” and other terms that include these). The use of these terms isintended to facilitate an understanding of the invention throughreference to the drawings, and the technological scope of the presentinvention is not limited by the meanings of these terms. Numbers thatare the same in two or more drawings refer to the same portion ormember. A number of embodiments will be described in order to facilitatean understanding of the invention, but these embodiments are notmutually exclusive, and parts that can be shared will apply to thedescription of other embodiments.

Embodiment 1

FIG. 1 is a schematic top view of the light emitting device 100 inEmbodiment 1, FIG. 2 is a schematic cross sectional view along the A-Aline in FIG. 1 and FIG. 3 is a schematic lower view of the lightemitting device in Embodiment 1.

The light emitting device in this embodiment includes: a light emittingelement 1 having a top surface which serves as a light emitting face,and having a lower surface (i.e., opposite side from the light emittingface on which electrodes are provided; a light reflecting member 2 thatis disposed so as to cover the lateral surfaces of the light emittingelement 1 and expose the top surface of the light emitting element 1;and a frame 4 that is formed on the light reflecting member 2, so as tosurround the outer periphery of the top surface of the light emittingelement 1. The light emitting device 100 further has a lighttransmissive member 3 that is disposed inside the frame 4, in otherwords, the light transmissive member 3 that fills the area surrounded bythe frame 4, and a sealing member 5 that covers the light reflectingmember 2, the frame 4, and the light transmissive member 3.

With the light emitting device 100 in Embodiment 1, the light emittingelement 1 has a structure that, for example, a semiconductor layer isstacked on a light transmissive insulating mounting board, and at leastone pair of positive and negative electrodes is formed on one surface onthe semiconductor layer side. The light reflecting member 2 is providedso as to cover at least the lateral surfaces of the light emittingelement 1.

The light emitting element 1 in this embodiment is flip-chip mountedwith a bump or other such bonding material on a mounting board 8, andits lateral surfaces are in contact with and covered by the lightreflecting member 2 as shown in FIG. 2. Wiring 9 is provided on the topsurface of the mounting board 8, and wiring 9 is joined to theelectrodes of the light emitting element 1 via a joining member. A shapein plan view of the light emitting element 1 is substantially square,and four pieces of the light emitting elements are arranged in a 2×2array (i.e., lattice shape) as shown in FIG. 1.

The spacing between the adjacent light emitting elements is preferablyless than the length of one side of the light emitting elements. Inparticular, using a spacing in a range of 1 to 300 μm, and preferably ina range of 50 to 100 μm, allows a phosphor or a light diffusing materialto be used to diffuse light in the non-light-emission area between thelight emitting elements. Therefore, the light reflecting member 2 ispreferably disposed in between the adjacent light emitting elements.

The light reflecting member 2 preferably covers all of the lateralsurfaces, excluding the top surface of the light emitting element 1.This is for the purpose of reducing light to be absorbed between lightemitting elements. Also, a top surface of the light reflecting member ispreferably flat. This top surface may be substantially flush with thetop surfaces of the light emitting elements, or may be positioned higherthan the top surfaces of the light emitting elements. The term “flush”here means that it is permitted for a slight, unintentional concave partformed on the surface due to the weight of the resin itself, in otherwords, it is permitted for there to be a difference of about a few dozenmicrons in the height. Furthermore, the light reflecting member 2 mayembed components other than the light emitting element 1 (such as theprotective element 16 shown in FIG. 1), mounted on the mounting board 8.At least one pair of terminal electrodes 18 is provided on the lowersurface of the mounting board 8 as shown in FIG. 3. The shapes of thesetwo terminal electrodes 18 may be made somewhat different from eachother, for example, by using a cutoff or the like, thereby making ananode mark or a cathode mark to show the polarity.

The frame 4 is formed on the top surface of the light reflecting member2. The frame 4 surrounds the outer periphery of the top surface of thelight emitting elements 1. As shown in FIG. 1, when a plurality of lightemitting elements 1 are used, the frame 4 is disposed so as to surroundthe outermost periphery of these light emitting elements 1. Preferably,the frame 4 is formed so that all of the top surfaces of the lightemitting elements 1 are exposed within the frame 4. For instance, it ispreferable the frame 4 is disposed on a position somewhat outside thetop surfaces of the light emitting elements 1 located the farthest tothe outside, and the top surface of the light reflecting member 2 isexposed on the outermost side within the frame 4. The distance betweenthe outer edges of the light emitting elements 1 and the inner walls ofthe frame 4 is, for example, 300 μm or less, and preferably in a rangeabout 0 μm to 100 μm. Thus limiting the light emission region allows thelight emitting device to exhibit higher luminance.

The frame 4 is preferably formed along the outer edges on the topsurfaces of the light emitting elements. The frame 4 can be formed froma resin material that is a mixture of substances having light reflectiveproperty. The height of the frame 4 is preferably about 50 to 500 μm.

The light transmissive member 3 is disposed within the frame 4, andspecifically in the recess surrounded by the frame 4. In thisembodiment, the recess has a bottom surface formed by the top surfacesof the light emitting elements 1 and the top surface of the lightreflecting member 2, and an inner surface formed by the frame 4. Thelight transmissive member 3 is disposed within the recess.

For the light transmissive member 3, a material in which a phosphor orother such wavelength conversion substance is contained in a resinmaterial, is preferably used. The light transmissive member 3 can beformed by dropping (i.e., potting) the resin material into the frame 4.In the case where a phosphor is used, the phosphor is preferably incontact with the top surface of the light emitting element 1 in orderfor heat generated from the phosphor during wavelength conversion to bedissipated efficiently, and thus the phosphor is preferably disposed onthe bottom surface of the recess, in other words, allowed to settle onthe light emitting element side.

FIG. 4 is a detail view of the area near the light emitting element 1 inFIG. 2. As shown in FIG. 4, inside the frame 4, the light transmissivemember 3 preferably has a two-layer structure consisting of a phosphorlayer 14 and a diffusion layer 12. Such two-layer structure can beformed by dropping the resin material containing the light diffusingmaterial and a phosphor with a higher specific gravity than this lightdiffusing material into the frame 4, and allowing the phosphor tosettle. The light diffusing material with a lower specific gravity isdispersed above the phosphor. The settling may be forced settling by,for example, centrifugal settling, or may be natural settling. By usingthe light diffusing material, the dark parts between adjacent lightemitting elements may be less recognizable, and quality of light can beimproved by making the light emitting device as if being a point lightsource.

The sealing member 5 is light transmissive, which is provided in orderfor light from the light emitting elements (i.e., light emitted throughthe light transmissive member 3) to be extracted more efficiently. Thesealing member 5 covers the light reflecting member 2, the frame 4, andthe light transmissive member 3. The sealing member 5 also has lenscomponent 6 and a flange 7 that sticks out to the outer peripheral sideof the lens, below the lens component 6.

As shown in FIG. 1, part of the frame 4 is covered by the flange 7. Inorder to increase light extraction efficiency, the lens component 6 ispreferably large enough that not all of the light emitted from the lightemitting elements will be reflected at the interface of the lenscomponent. However, there is a limit to increase the lens size whilestill attempting to downsize the light emitting device. In view of this,part of the frame 4 shall be covered by the flange 7. In other words,part of the frame 4 is disposed straddling the lens component 6 and theflange 7 in plan view. More preferably, as shown in FIG. 1, part of theouter edge of the frame 4 is covered by the flange 7, whereas the innersurface of the frame 4, that is, the outer edge of the lighttransmissive member 3, is entirely disposed under the lens component 6.This the light emitting device to be downsized without reduction in thelight extraction efficiency as much as possible.

Also, it is preferable for the end faces of the sealing member 5 and themounting board 8 to be flush so that the outer edge of the sealingmember 5 and the outer edge of the mounting board 8 will match up in topview.

Method for Manufacturing Light Emitting Device of Embodiment 1

The method for manufacturing the light emitting device of Embodiment 1is the method for manufacturing the above-mentioned light emittingdevice 100, which includes a light emitting element mounting step, alight reflective member formation step, a frame formation step and lighttransmissive member formation step, as shown in FIGS. 5A to 10B.

Mounting of Light Emitting Element

In mounting process of the light emitting element, a mounting board 81is provided, and light emitting elements 1 are mounted on the mountingboard 81 as shown in FIGS. 5A and 5B each illustrating a schematic topview and a schematic side view. The mounting board 81 is in the form ofa board, with wiring 9 formed on the top surface and metal membersserving as terminal electrodes 18 formed on the lower surface. Thewiring 9 and the terminal electrodes 18 are electrically connected byvias or the like inside the mounting board.

Then, the light emitting elements 1 are flip-chip mounted on the topsurface of the mounting board 81 via bonding members as shown in FIGS.6A and 6B, which each show a schematic top view and a schematic sideview, respectively. The connection between the light emitting elements 1and the wiring 9 of the mounting board 81 can be made using bumps,solder, conductive paste, anisotropic conductive paste, or another suchbonding member. The protective element 16 may be mounted either beforeor after the mounting of the light emitting elements 1. Usually, themounting board 81 is an assembly in which a plurality of mounting boards8 are continued, until being divided in a subsequent step. Thedescription here will make use of a drawing in which two mounting boards8 are linked.

After the light emitting elements 1 are mounted on the mounting board,the spaces between the top surface of the mounting board and the lowersurfaces of the light emitting elements 1 may optionally be under-filledto lessen the stress with the light reflecting member 2. By formingunder-fill, the light reflecting member 2 less likely to enter thespaces between the top surface of the mounting board and the lowersurfaces of the light emitting elements, and therefore increasesreliability. This is because when the light reflecting member 2 enterinto the lower surfaces of the light emitting elements 1, there is therisk that the light reflecting member 2 will expand by heat and lift upthe light emitting elements 1. Providing the under-fill is alsopreferable because it can have a light reflecting function, allowing thelight emitted toward the mounting board 8 to be reflected.

The arrangement of the light emitting elements 1 can be suitablydetermined according to the size of the light emitting elements beingused, and the specifications of the light emitting device ultimately tobe obtained. For example, they can be arranged in a array, with the topsurfaces of a plurality of light emitting elements forming a singlelight emitting region.

Formation of Light Reflecting Member

FIGS. 7A and 7B show a schematic top view and a schematic crosssectional view along the B-B′ line in FIG. 7A, respectively illustratingthat the lateral surfaces of the light emitting elements 1 are coveredby the light reflecting member 2 so that the top surfaces of the lightemitting elements 1 are exposed. Preferably, the top surface of theprotective element 16 is positioned lower than the top surfaces of thelight emitting elements 1, and top surface of the protective element 16is covered by the light reflecting member 2. Accordingly, lightabsorption by the protective element 16 may be reduced. The top surfaceof the light emitting elements 1 and the top surface of the lightreflecting member 2 are preferably at the same height, that is, aresubstantially flush.

The light reflecting member 2 can be formed by providing a dam materialaround the outside of the mounting board assembly, and pouring a resinmaterial, which contains a light reflecting member, into this dam. Theviscosity and so forth are adjusted so that the spaces between adjacentlight emitting elements 1 are properly filled in.

Formation of Frame

FIGS. 8A and 8B show a schematic top view and a schematic crosssectional view along the C-C′ line in FIG. 8A, respectively illustratingthat the frame 4 is then formed so as to surround the top surfaces ofthe light emitting elements 1. The frame 4 can be formed, for example,using a resin discharge apparatus to discharge a circular shape of resinover the light reflecting member 2. Alternatively, the frame that hasbeen molded ahead of time in a metal mold or the like may betransfer-printed and affixed onto the light reflecting member 2, or aninkjet device, a 3D printer, or the like may be used to form the frame4. In this embodiment, the frame 4 is formed along about the outer 100μm to the outer edges of the top surfaces of the light emitting elements1, and in a quadrilateral shape whose corners are rounded in plan view.

Formation of Light transmissive Member

FIGS. 9A and 9B show a schematic top view and a schematic crosssectional view along the D-D′ line in FIG. 9, respectively illustratingthat the light transmissive member 3 is disposed inside the frame 4. Inthis embodiment, a resin material which contains a phosphor and a lightdiffusing material is potted in the region bounded by the frame 4,thereby filling in the frame 4. Thereafter, the phosphor allows to be incontact with the top surfaces of the light-emitting elements 1 due tothe natural setting, the phosphor layer 14 is formed near the lightemitting elements, and the diffusion layer 12 thereon (see FIG. 4).

Sealing Member Formation Step

FIGS. 10A and 10B show a schematic top view and a schematic side view,respectively illustrating that the sealing member 5 is formed on thelight reflecting member 2, the frame 4, and the light transmissivemember 3. To make the description easier to understand, the lightreflecting member 2 is shown as see-through so that the light emittingelement 1 and the protective element 16 can be seen. The sealing member5 can be formed by a variety of methods, such as transfer molding,compression molding, coating (i.e., potting) with a resin, and moldingwith a casting case. The sealing member 5 here is formed so as to havethe lens component 6 and the flange 7, and is disposed so that part ofthe frame 4 is located at the bottom part of the flange 7. In formingthe sealing member 5 by compression molding, it is preferable to form anair vent 20 in the flange 7. Accordingly, the lens shape is stabilized.

Separation

Finally, the flange 7 between adjacent lens components 6 (the X-X linein FIGS. 10A and 10B) is cut by dicing or another such method to obtainthe light emitting device of Embodiment 1. Consequently, the endsurfaces of the mounting board 8, the light reflecting member 2, and thesealing member 5 are flush. The cut surfaces become the outer edges ofthe light emitting devices, so the yield can be increased.

As shown in FIG. 5, in this embodiment, the circuit placed in the lightemitting devices in which the four light emitting elements arerespectively mounted have been disposed have the pattern of the wiring9, which is two in series and two in parallel, but the wiring patterncan be suitably modified to match the desired circuit. FIG. 11 shows anexample of the wiring 9 in the case where the four light emittingelements are in serial connection. The number of mounted light emittingelements may also be just one.

Embodiment 2

As shown in FIG. 12, the light emitting device 200 in Embodiment 2differs from the light emitting device 100 in Embodiment 1 in that thereis no mounting board on which the light emitting element 1 is to bemounted. Because there is no mounting board, electrodes 21 are exposedfrom the lower surface of the light reflecting member 2.

Because the light emitting device in Embodiment 2 configured as abovehas no mounting board, it can be thinner and more compact. Thisdownsized light emitting device also allows for higher-density mounting.

Method for Manufacturing Light Emitting Device of Embodiment 2

As shown in FIG. 13, the method for manufacturing the light emittingdevice 200 of Embodiment 2 is configured the same as the manufacturingmethod in Embodiment 1, except that a support member 24 is used insteadof the mounting board 8 that is used in the method for manufacturing alight emitting device of Embodiment 1. The light emitting device 200 canbe formed by the same manufacturing method as in Embodiment 1, exceptthat the support member 24 is separated off (i.e., removed) as indicatedby the dotted line in FIG. 13 after the sealing member 5 is formed.

Embodiment 3

The light emitting device 300 of Embodiment 3 can mainly be used toadvantage as a light source for a backlight or the like. It differs fromEmbodiment 1 in the shape of the sealing member 5.

FIG. 14 is a cross section of the light emitting device 300 and anoptical member 30 provided in contact with the sealing member 5, whichshows the cross section in the thickness direction of the opticalmember. As shown in FIG. 14, the sealing member 5 has a flat surfacethat can be connected to the optical member 30, such as a light guideplate or a light guide film. In Embodiment 3, the sealing member 5 has ashape that spreads outward toward the top (i.e., the opposite side fromthe back surface of the mounting board 8). The lateral surfaces of thesealing member 5 are curved. Also, the sealing member 5 is not incontact with the mounting board 8, and covers the top surface of thelight reflecting member 2 exposed on the outside of the frame 4, theouter walls of the frame 4, and the top surface of the lighttransmissive member 3. Accordingly, good quality of light is efficientlyincident on the optical member.

In the case where the sealing member 5 is brought into contact with anedge-type light guide plate, the light emitting device is preferably athin type. “Thin type” in this case refers to the length in the depthdirection of the drawings (that is, the thickness direction of the lightguide plate).

In this case, the light emitting element 1 mounted on the mounting board8 is preferably rectangular in plan view, and the frame is longer in thelengthwise direction of the light emitting element and shorter in theshort-side direction to match the shape of the light emitting element.To reduce thickness, the frame may be formed so as to be thinner in thelengthwise direction than in the short-side direction.

The materials and so forth used for the each structure member of thelight emitting device in this embodiment will now be described.

Mounting Board 8

The mounting board on which the light emitting element 1 is mounted isusually formed from glass epoxy, resins, ceramics (e.g., HTCC, LTCC) oranother such insulating material, a composite of an insulating materialand a metal member, or the like. The mounting board is preferably madeof a ceramic or a thermosetting resin which have characteristics of highheat resistance and high environmental resistance. Examples of theceramic include alumina, aluminum nitride, mullite and the like. Amongthem, aluminum nitride is particularly preferred due to having high heatdissipation. The mounting board may be made of ceramic combined with aninsulating material such as BT resin, glass epoxy or epoxy resin.Examples of the thermosetting resin include epoxy resin, a triazinederivative epoxy resin, modified epoxy resin, silicone resin, modifiedsilicone resin, acrylate resin and a urethane resin. Among them, atriazine derivative epoxy resin is preferred. The mounting board ispreferably flat plate-like shape.

Wiring 9

The mounting board has wiring on its surface and/or in its interior, andthe wiring is connected to the light emitting element. The wiring can beformed by a metal such as copper, aluminum, gold, silver, tungsten, ironand nickel, or an alloy such as iron-nickel alloy or phosphor bronze.The thickness of the wiring is, for example, in a range of a fewmicrometer to several hundred micrometer.

Light Emitting Element 1

For the light emitting element 1, a light emitting diode chip or anothersuch semiconductor light emitting element can be used. The semiconductorlight emitting element may include a light transmissive substrate, and asemiconductor layer formed thereon. Examples of materials used for thelight transmissive substrate include a light transmissive insulatingmaterial such as sapphire (Al₂O₃), and a semiconductor material thattransmits light emitted from the semiconductor layer (e.g., a nitridebased semiconductor material).

The semiconductor stack includes multi-layer semiconductor such as ann-type semiconductor layer, a light emitting layer (active layer) and ap-type semiconductor layer. The semiconductor layer may be formed of asemiconductor such as ones of Group III-V compound semiconductormaterial and Group II-VI compound semiconductor material. Specifically,a nitride-based semiconductor material such as In_(X)Al_(Y)Ga_(1-X-Y)N(0≦X, 0≦Y, X+Y≦1) can be used.

The light emitting element has a pair of electrodes. The electrodes maybe disposed on the same side with respect to the semiconductor laminate(i.e., the light emitting layer), or on the different side with respectto the semiconductor laminate. A good electrical conductor can be usedas the electrodes of the light emitting elements, with copper or anothersuch metal being preferable, for example.

Light Reflecting Member 2

The light reflecting member is an insulating member, and can beconstituted by a light reflecting resin with a certain degree ofstrength. The term “light reflecting resin” means a resin whosereflectivity of the light from the light emitting element is high, forexample, the reflectivity is 70% or higher.

The light reflecting resin can be obtained by dispersing a lightreflecting substance in a light transmissive resin, for example.Examples of the light reflecting substances preferably include titaniumoxide, silicon dioxide, zirconium dioxide, potassium titanate, alumina,aluminum nitride, boron nitride and mullite. The light reflectingsubstance can be in the form of particles, fibers, flakes, or the like.Among them, a fibrous material is particularly preferable because thecoefficient of thermal expansion of the light reflecting member can belowered to reduce the difference in the coefficient of thermal expansionbetween the light emitting elements, for example. The resin materialforming the light reflecting resin is preferably made of a thermosettinglight transmissive resin such as a silicone resin, silicone-modifiedresins, epoxy resins and a phenol resin.

Frame 4

The frame 4 can function as a reflecting member for improving theemission efficiency of the light emitting device by reflecting upwardthe light that is emitted to the side from the light emitting element 1by the inner wall surfaces.

The frame preferably makes use of a material that can be applied in aliquid or a paste state on the light reflecting member 2, and hardeningit as it is. In order to form the frame tall enough to serve as a damwhen filled with the light transmissive member, it is preferable to beuse a material in a paste state, that is, a liquid of high viscosity(e.g., in a range of 380 to 450 Pa·s of viscosity at 25° C.). Examplesof such a material include thermosetting resins and thermoplastic resinssuch as a phenol resin, an epoxy resin, a BT resin, a PPA and a siliconeresin. Also, the frame is preferably white in order to increase itsreflectivity. To increase its reflectivity even more, a powder of lightreflecting material (e.g., TiO₂, Al₂O₃, ZrO₂, MgO, ZnO) may be dispersedin the resin material before forming the frame. The power of lightreflecting material herein can have a large difference in refractiveindex with respect to the resin used as a base material, and does notreadily absorb light emitted by the light emitting element.

A height of the frame from the mounting board can be appropriatelyspecified, but as shown in FIG. 4, it is preferably tall enough to allowthe phosphor layer 14 and the diffusion layer 12 to be formedseparately. A width of the frame in plan view (i.e., the thickness ofthe walls) can be appropriately specified as well.

Light Transmissive Member 3

The light transmissive member can employ a light transmissive resin thatis commonly used in the sealing of light emitting devices in which alight emitting diode or the like is installed. More specifically,silicone resins, epoxy resins, and urea resins can be used. Also, sincethe previously formed frame serves as a dam, the light transmissiveresin can be formed from a liquid resin material with a relatively lowviscosity (e.g., in a range of 0.01 to 5.0 Pa·s of viscosity at 25° C.),which means that filling will be easy even if the area is small.

When a wavelength conversion substance, for example, a substance havinga certain amount of specific gravity, such as a phosphor, is mixed intothis low-viscosity resin material, since the wavelength conversionsubstance tends to settle before curing of the resin is completed, thewavelength conversion substance is distributed more near the surface(the top surface) of the light emitting element 1 mounted on themounting board 8, so that light emitted by the light emitting element 1is converted into the suitable wavelength. Also, this resin material maycontain a colorant, a light diffusing material, a filler, or the like,in addition to the above-mentioned wavelength conversion substance,depending on the intended purpose and application.

The wavelength conversion substance contained in the light transmissivemember will now be described.

Wavelength Conversion Substance

The wavelength conversion substance may be one at least capable of beingexcited by the light emitted from the light emitting element, andthereby emits light of a different wavelength. Examples thereofincludes; (i) garnet-based phosphors such as aluminum-garnet-basedphosphors, e.g., yttrium-aluminum-garnet (YAG)-based phosphors activatedby cerium, lutetium-aluminum-garnet (LAG)-based phosphors activated bycerium, (ii) nitrogen-containing calcium aluminosilicate(CaO—Al₂O₃—SiO₂)-based phosphors activated by europium and/or chromium,

-   -   (iii) silicate ((Sr, Ba)₂SiO₄)-based phosphors activated by        europium, (iv) β-SiAlon-based phosphors,    -   (v) nitride-based phosphors such as CASN-based (CaAlSiN₂:Eu) or        SCASN-based phosphors,    -   (vi) rare earth nitride phosphors such as LnSi₃N₁₁-based        phosphors, LnSiAlON-based phosphors (Ln is a rare earth        element), (vii) oxynitride-based phosphors such as        BaSi₂O₂N₂-based phosphors, Ba₃Si₆O₁₂N₂-based phosphors activated        by europium, (viii) fluoride complex phosphor phosphors        activated by manganese (K₂SiF₆:Mn), (ix) sulfide-based phosphors        such as CaS-based phosphors (CaS:Eu), SrGa₂S₄-based phosphors        (SrGa₂S₄:Eu), SrAl₂O₄-based phosphors, ZnS-based phosphors,        and (x) chloro-silicate-based phosphors, and the like.

Examples of the phosphor may include a luminescent material referred toas a so called nanocrystal or quantum dot, which each is nano-sizehigh-dispersive particles of semiconductor materials, for example GroupII-VI, Group III-V and Group IV-VI semiconductors, more specificallyCdSe, core-shell type CdS_(X)Se_(1-X)/ZnS, GaP, InP, and GaAs. Thequantum dot phosphor may be unstable, and therefore may besurface-covered or stabilized with a resin such as PMMA (polymethylmethacrylate), a silicone resin, an epoxy resin, a hybrid resin ofthese, and the like.

Underfill

Underfill preferably has a coefficient of thermal expansion which isbetween that of the light reflecting member 2 and the light emittingelement 1. Particularly, the coefficient of thermal expansion of theunderfill is preferably closer to that of the light emitting element 1than that of the light reflecting member 2.

The underfill contains a filler so that a coefficient of thermalexpansion can be made to approach a coefficient of thermal expansion ofthe light emitting element 1. The material of the underfill isappropriately selected in particular as long as it is less likely toabsorb light from the light emitting element. For example, the materialincludes an epoxy resin, a silicone resin, a modified-silicone resin, aurethane resin, an oxetane resin, an acrylic material, a polycarbonateresin, and a polyimide resin.

In the case where the underfill contains the white filler, the light ismore likely to be reflected, and the light extraction efficiency can beimproved. For a material of the filler, inorganic compound is preferablyused. Here, the “white filler” includes one which looks white whenscattered due to a difference in refractive index from a material aroundthe filler even when the filler is transparent itself.

Support Member 24

The support member is removed after the light emitting element 1 ismounted in place and at least after the light reflecting member 2 hasbeen formed. Accordingly, the light emitting device can be more compact.The material can be appropriately selected, and the support member maybe in a sheet-like or a plate-like shape.

Sealing Member 5

Examples of the light transmissive member forming the sealing memberinclude a thermosetting resin such as a silicone resin, asilicone-modified resin, an epoxy resin, a phenol resin, and athermoplastic resins such as a polycarbonate resin, an acrylic resin, amethylpentene resin, a polynorbomene resin. Among them, a silicone resinis particularly preferable as the light transmissive member due tohaving good resistance to light and environment.

It is to be understood that although the present invention has beendescribed with regard to preferred embodiments thereof, various otherembodiments and variants may occur to those skilled in the art, whichare within the scope and spirit of the invention, and such otherembodiments and variants are intended to be covered by the followingclaims.

What is claimed is:
 1. A light emitting device comprising: a lightemitting element having a top surface and a lateral surface; a lightreflecting member that is disposed so as to cover the lateral surface ofthe light emitting element and expose the top surface of the lightemitting element; a frame that is disposed on the light reflectingmember so as to surround an outer periphery of the top surface of thelight emitting element; a light transmissive member that is lighttransmissive and disposed inside the frame; and a sealing member thatcovers the light reflecting member, the frame and the light transmissivemember, the sealing member having a curved portion and a flange arrangedin an outer periphery of the curved portion with a top surface of thecurved portion being positioned higher than a top surface of the flange,wherein the flange covers part of the frame.
 2. The light emittingdevice according to claim 1, wherein the light transmissive membercontains a wavelength conversion substance.
 3. The light emitting deviceaccording to claim 2, wherein the wavelength conversion substance issettled on the light emitting element side in the light transmissivemember.
 4. The light emitting device according to claim 1, wherein thetop surface of the light emitting element is substantially flush with atop surface of the light reflecting member.
 5. The light emitting deviceaccording to claim 1, further comprising a protective element that isembedded in the light reflecting member.
 6. The light emitting deviceaccording to claim 1, wherein a plurality of light emitting elements aremounted on a top surface of the mounting board, and spacing between theadjacent light emitting elements is in a range of 1 μm to 300 μm.
 7. Thelight emitting device according to claim 1, further comprising amounting board having terminal electrodes on a lower surface of themounting board, wherein the light emitting element is mounted on a topsurface of the mounting board.
 8. The light emitting device according toclaim 1, wherein the light transmissive member contains a lightdiffusing material.
 9. The light emitting device according to claim 1,wherein the light reflecting member is in contact with the lateralsurface of the light emitting element.
 10. A light emitting devicecomprising: a light emitting element having a top surface and a lateralsurface; a light reflecting member that is disposed so as to cover thelateral surface of the light emitting element and expose the top surfaceof the light emitting element; a frame that is disposed on the lightreflecting member so as to surround an outer periphery of the topsurface of the light emitting element; a light transmissive member thatis light transmissive and disposed inside the frame; and a sealingmember that covers the light reflecting member, the frame and the lighttransmissive member, the sealing member also having a flange wherein theflange covers part of the frame, wherein the light emitting element hasa semiconductor layer and a pair of electrodes disposed on a same sideof the semiconductor layer, and the pair of electrodes are exposed froma lower surface of the light reflecting member.
 11. The light emittingdevice according to claim 10, wherein the top surface of the lightemitting element is substantially flush with a top surface of the lightreflecting member.
 12. The light emitting device according to claim 10,further comprising a protective element that is embedded in the lightreflecting member.
 13. The light emitting device according to claim 10,further comprising a mounting board having terminal electrodes on alower surface of the mounting board, wherein the light emitting elementis mounted on a top surface of the mounting board.
 14. The lightemitting device according to claim 10, wherein the light reflectingmember is in contact with the lateral surface of the light emittingelement.
 15. A light emitting device comprising: a light emittingelement having a top surface and a lateral surface; a light reflectingmember that is disposed so as to cover the lateral surface of the lightemitting element and expose the top surface of the light emittingelement; a frame that is disposed on the light reflecting member so asto surround an outer periphery of the top surface of the light emittingelement; a light transmissive member that is light transmissive anddisposed inside the frame with an outer perimeter of the lighttransmissive member being defined by the frame; and a sealing memberthat covers the light reflecting member, the frame and the lighttransmissive member, the sealing member having a flange wherein theflange covers part of the frame.
 16. The light emitting device accordingto claim 15, wherein the top surface of the light emitting element issubstantially flush with a top surface of the light reflecting member.17. The light emitting device according to claim 15, further comprisinga protective element that is embedded in the light reflecting member.18. The light emitting device according to claim 15, further comprisinga mounting board having terminal electrodes on a lower surface of themounting board, wherein the light emitting element is mounted on a topsurface of the mounting board.
 19. The light emitting device accordingto claim 15, wherein the light reflecting member is in contact with thelateral surface of the light emitting element.